<!--
 * @Description: 优先级
 * @Author: zzj
 * @Date: 2021-08-13 11:16:26
 * @LastEditors: zzj
 * @LastEditTime: 2021-08-16 12:09:58
 * @FilePath: \jiepuyiqing\tyut\zzj\2-css\day03\1-优先级.html
-->
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>优先级</title>
    <style>
        ul.menu{

        }
        ul.menu > li.menu_item{

        }
        ul.menu > li.menu_item > ul.sub_menu{
            
        }
        ul.menu > li.menu_item > ul.sub_menu > li{
            color: turquoise;
            line-height: 2em;
        }
        #introduce{
            color: tomato;
            background-color: teal;
        }
        .si{
            color: yellow !important;
            border: 3px solid #ccc;
        }
    </style>
</head>
<body>
    <div class="tyut">
        <!-- 头部-->
        <header>
            <div class="first_line"> </div>
            <div class="second_line">
                <div class="logo">logo</div>
                <!-- ul 菜单列表 -->
                <ul class="menu">
                    <li class="menu_item">
                        <span>学校概况</span>
                        <ul class="sub_menu">
                            <li class="si" style="color: violet;" id="introduce">学校简介</li>
                            <li id="histroy">历史沿革</li>
                        </ul>
                    </li>
                    <li class="menu_item">
                        <span>人才培养</span>
                        <ul class="sub_menu">
                            <li>本科生教育</li>
                            <li>研究生教育</li>
                        </ul>
                    </li>
                </ul>
            </div>
        </header>
        <!-- /头部 -->
        <!-- 内容 -->
        <!-- /内容 -->
        <!-- 脚部 -->
        <footer>
            <div class="first_line"></div>
            <address>地址</address>
        </footer>
        <!-- /脚部 -->
    </div>
</body>
</html>